2 * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2014 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "command-line.h"
22 #include "dynamic-string.h"
23 #include "ovs-thread.h"
27 VLOG_DEFINE_THIS_MODULE(command_line);
29 /* Given the GNU-style long options in 'options', returns a string that may be
30 * passed to getopt() with the corresponding short options. The caller is
31 * responsible for freeing the string. */
33 long_options_to_short_options(const struct option options[])
35 char short_options[UCHAR_MAX * 3 + 1];
36 char *p = short_options;
38 for (; options->name; options++) {
39 const struct option *o = options;
40 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
42 if (o->has_arg == required_argument) {
44 } else if (o->has_arg == optional_argument) {
52 return xstrdup(short_options);
55 /* Given the GNU-style options in 'options', prints all options. */
57 print_options(const struct option options[])
59 struct ds ds = DS_EMPTY_INITIALIZER;
61 for (; options->name; options++) {
62 const struct option *o = options;
63 const char *arg = o->has_arg == required_argument ? "ARG" : "[ARG]";
65 ds_put_format(&ds, "--%s%s%s\n", o->name, o->has_arg ? "=" : "",
66 o->has_arg ? arg : "");
67 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
68 ds_put_format(&ds, "-%c %s\n", o->val, o->has_arg ? arg : "");
71 printf("%s", ds.string);
75 /* Runs the command designated by argv[0] within the command table specified by
76 * 'commands', which must be terminated by a command whose 'name' member is a
79 * Command-line options should be stripped off, so that a typical invocation
80 * looks like "run_command(argc - optind, argv + optind, my_commands);". */
82 run_command(int argc, char *argv[], const struct command commands[])
84 const struct command *p;
87 ovs_fatal(0, "missing command name; use --help for help");
90 for (p = commands; p->name != NULL; p++) {
91 if (!strcmp(p->name, argv[0])) {
93 if (n_arg < p->min_args) {
94 VLOG_FATAL( "'%s' command requires at least %d arguments",
95 p->name, p->min_args);
96 } else if (n_arg > p->max_args) {
97 VLOG_FATAL("'%s' command takes at most %d arguments",
98 p->name, p->max_args);
100 p->handler(argc, argv);
101 if (ferror(stdout)) {
102 VLOG_FATAL("write to stdout failed");
104 if (ferror(stderr)) {
105 VLOG_FATAL("write to stderr failed");
112 VLOG_FATAL("unknown command '%s'; use --help for help", argv[0]);
118 static struct ovs_mutex proctitle_mutex = OVS_MUTEX_INITIALIZER;
120 /* Start of command-line arguments in memory. */
121 static char *argv_start OVS_GUARDED_BY(proctitle_mutex);
123 /* Number of bytes of command-line arguments. */
124 static size_t argv_size OVS_GUARDED_BY(proctitle_mutex);
126 /* Saved command-line arguments. */
127 static char *saved_proctitle OVS_GUARDED_BY(proctitle_mutex);
129 /* Prepares the process so that proctitle_set() can later succeed.
131 * This modifies the argv[] array so that it no longer points into the memory
132 * that it originally does. Later, proctitle_set() might overwrite that
133 * memory. That means that this function should be called before anything else
134 * that accesses the process's argv[] array. Ideally, it should be called
135 * before anything else, period, at the very beginning of program
138 proctitle_init(int argc, char **argv)
142 assert_single_threaded();
143 if (!argc || !argv[0]) {
144 /* This situation should never occur, but... */
148 ovs_mutex_lock(&proctitle_mutex);
149 /* Specialized version of first loop iteration below. */
150 argv_start = argv[0];
151 argv_size = strlen(argv[0]) + 1;
152 argv[0] = xstrdup(argv[0]);
154 for (i = 1; i < argc; i++) {
155 size_t size = strlen(argv[i]) + 1;
157 /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
158 if (argv[i] + size == argv_start) {
159 /* Arguments grow downward in memory. */
162 } else if (argv[i] == argv_start + argv_size) {
163 /* Arguments grow upward in memory. */
166 /* Arguments not contiguous. (Is this really Linux?) */
169 /* Copy out the old argument so we can reuse the space. */
170 argv[i] = xstrdup(argv[i]);
172 ovs_mutex_unlock(&proctitle_mutex);
175 /* Changes the name of the process, as shown by "ps", to the program name
176 * followed by 'format', which is formatted as if by printf(). */
178 proctitle_set(const char *format, ...)
183 ovs_mutex_lock(&proctitle_mutex);
184 if (!argv_start || argv_size < 8) {
188 if (!saved_proctitle) {
189 saved_proctitle = xmemdup(argv_start, argv_size);
192 va_start(args, format);
193 n = snprintf(argv_start, argv_size, "%s: ", program_name);
195 n += vsnprintf(argv_start + n, argv_size - n, format, args);
197 if (n >= argv_size) {
198 /* The name is too long, so add an ellipsis at the end. */
199 strcpy(&argv_start[argv_size - 4], "...");
201 /* Fill the extra space with null bytes, so that trailing bytes don't
202 * show up in the command line. */
203 memset(&argv_start[n], '\0', argv_size - n);
208 ovs_mutex_unlock(&proctitle_mutex);
211 /* Restores the process's original command line, as seen by "ps". */
213 proctitle_restore(void)
215 ovs_mutex_lock(&proctitle_mutex);
216 if (saved_proctitle) {
217 memcpy(argv_start, saved_proctitle, argv_size);
218 free(saved_proctitle);
219 saved_proctitle = NULL;
221 ovs_mutex_unlock(&proctitle_mutex);
223 #else /* !__linux__ */
224 /* Stubs that don't do anything on non-Linux systems. */
227 proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
231 #if !(defined(__FreeBSD__) || defined(__NetBSD__))
232 /* On these platforms we #define this to setproctitle. */
234 proctitle_set(const char *format OVS_UNUSED, ...)
240 proctitle_restore(void)
243 #endif /* !__linux__ */